In manufacturing of large rotating equipment, such as, for example turbine generators, much effort is extended in obtaining the exact size of shafts, bearings, and other components of the machinery and accurately aligning such components. Regardless of the accuracy and the efforts in manufacturing such heavy machinery to close tolerances, when the machine is assembled in position and placed upon the foundation or support, the machinery must be accurately leveled and aligned so that no portion of the apparatus buckles or is under undue stress because of lack of the proper leveling and support. Such lack of leveling may occur at the time of installation or at a later time if the support shifts in the position even slightly because of crushing or deterioration of the support.
In the past, it has been customary in installing a large piece of rotating machinery to arrange a plurality of accurately level sub-sole plates to support a main sole or foundation plate which is secured to a concrete or base foundation by means of foundation bolts. Accurately leveling the sub-sole plate was a long, tedious and expensive process and frequently required the use of shims or other adjusting or filler devices. Furthermore, since there were a number of sub-sole plates which had to be brought to the same level position, an inaccuracy in one such sub-sole plate could produce undesired stresses in the frame and other components of the machinery. After a period of use, any shims may produce such stresses through corrosion or similar changes or through yielding under long sustained stresses.
In U.S. Pat. No. 3,190,041, a support for large machinery is described. The foundation comprises a base portion which may be formed of concrete or metal or other material and a plurality of grout or mortar pads positioned between the base portion and the foundation plate. In forming the composite supporter foundation, a foundation plate is first placed in a level spaced position relative to the upper surface of the base portion by means of a plurality of leveling screws which threadedly engage a foundation plate and whose lower end engages the upper surface of the base portion. After the foundation plate has been accurately leveled by means of leveling screws, nuts are screwed on to the foundation bolts to secure the foundation plate in this level position. Metal washers or spacers may be positioned between the respective nuts and the upper surface of the plate.
After the foundation plate is rigidly secured in a leveled position above the upper surface of the base, mortar forms are position between the base and foundation plate, and a grouting material is ram-packed inside the mortar forms between the foundation plate and the upper surface of the base portion, thus forming mortar pads to support the foundation plate. After the pads have been completely cured, the foundation plates are removed so that the support pads for the foundation plate are cleaned up and the form removed from the support. Then, the foundation plate is repositioned on the grout or mortar pads, and then the heavy machinery would be attached to the foundation plate.
U.S. Pat. No. 4,331,314 describes an anchoring arrangement for a head pump/turbine discharge ring. The arrangement provides a pre-stressed anchor stud connected between an upper foundation ring and the flange portion of the discharge ring which is pre-stressed and affects the leveling to the discharge ring. The upper leveling plate is attached to a lower leveling plate embedded in concrete or similar foundation material, and is pre-stressed to grouting material between the foundation structure and the upper leveling ring.